Bane was born June 25, 1998. He was raised by his great grandparents, Bob and Fabbie Bane, and his guardian is his uncle, Tony Bane. Desmond focused on baseball until eighth grade, also playing football and soccer, but ultimately opted to pursue basketball. Bane played basketball for Seton Catholic High School, a small private institution in Richmond, Indiana. As a senior, he averaged a state-high 30 points, 11.5 rebounds, 6.1 assists and 3.2 blocks per game and was named the MVP of the Wettig Memorial Holiday Tournament. In his high school career, Bane scored 1,991 points, surpassing 1988 Indiana Mr. Basketball winner Woody Austin for the most in Wayne County history. After high school, Bane opted to play college ball for Texas Christian University. He played all four seasons at TCU and was named to the Second-team All-Big 12 as a junior and First-team All-Big 12 as a senior. Bane debuted for TCU in 2016-17, playing 39 games as a freshman and drawing 13 starts. He averaged 7.1 points, 2.9 rebounds and 1.0 assists in 20.7 minutes. He became a full-time starter as a sophomore, averaging 12.5 points, 4.1 rebounds and 2.5 assists in 30.5 minutes. Bane's role increased again as a junior, as he averaged 15.2 points, 5.7 rebounds, 2.4 assists and 1.1 steals in 35.5 minutes. Finally, as a senior, Bane averaged 16.6 points, 6.3 rebounds, 3.9 assists and 1.5 steals in 36.1 minutes. That resulted in him being voted to the All-Big 12 First Team. Arguably the best performance of his collegiate career was Nov. 30, 2018 in a win over Central Michigan, where Bane recorded 24 points (8-11 FG, 4-6 3Pt, 4-4 FT), nine rebounds, three assists, three blocks and one steal in 32 minutes.